Burner for oil-fired gas generator



Oct. 22, 1957 L. P. GAUCHER BURNER FOR OIL-FIRED GAS GENERATOR FiledJan. 17, 1952 Mg, OIL

2 CONTAINING GAS IN VEN TOR.

L eon R Gaucher United States atent BURNER FOR OIL-FIRED GAS GENERATORLeon P. Gaucher, Tuckahoe, N. Y., assignor to The Texas Company, acorporation of Delaware I Application January 17, 1952, Serial No.266,840

2 Claims. (Cl. 158-74) This invention relates to fluid fuel burners andmore particularly to fluid fuel burners of the kind used in flowtypesynthesis gas generators. The latter are essentially closed reactionchambers, housing burners, and are primarily used for the partialcombustion of gaseous, liquid, or partially vaporized liquidhydrocarbons in the manufacture of synthesis gas. For illustrativepurposes, the burner shown on the attached sheet of drawings is of atype primarily used for the partial combustion of oil to form carbonmonoxide and hydrogen.

In the past, burners of this type have been subject to frequent cloggingof the fuel orifices, and there have been many attempts in the prior artto provide a burner of this type with adequate cooling means to preventburner clogging and failure of the metal due to overheating. In spite ofthe fact that the oil or other liquid hydrocarbon may be supplied at asufliciently high rate to give it a rather high velocity in the burnerpassageways and orifices, the amount of cooling to be derived from thesupply of fuel alone has proved entirely inadequate. This appears to bedue to the fact, in spite of the high velocity of flow of the fuel inthe burner passageways and orifices, that there is always a thin film ofliquid hydrocarbon on the surface of these passageways which isstationary, or at least moving at a very slow rate. It appears that dueto the high temperatures encountered in these partial combustionprocesses, this film of slowly moving or stationary hydrocarbon willcoke-up, with the result that the passageway becomes first restricted,and ultimately completely clogged, necessitating a shut-down of thegenerator-and removal of the burner elements for a thorough cleaning.

'It is an object of this invention to provide a burner head which willovercome these operational difliculties.

It is a further object of this invention to provide a burner head inwhich a blanket of steam is maintained at the burner'face, in' betweenthe fuel and oxygen orifices.

' These and other objects of the invention will be apparent from thefollowing description read in conjunction with the attached sheet ofdrawings in which:

Figure 1 is a top plan view of the burner; and

Figure 2 is a side elevation, in section, of a preferred embodiment ofthis invention.

The burner head which is generally indicated by the reference numeral isshown as being an annular casting having a substantially frusto-conicaldepression 11, which may be machined out of the upper or flame-exposedsurface thereof. An annular cooling channel 12 surrounds the depression11, and provides a means for supplying a coolant, such as water, indirect heat exchange relation to the hottest part of the burner head 10.

Positioned below and extending longitudinally from the burner head arefirst, second and third concentric annular members 13, 14, and 15defining annular passageways 16, 17, and passageway 18. Thesepassageways terminate at the burner head 10, and each is connected byfurther closed passageways 19, 20, and 21, re-

2,810,433 Patented Oct. 22, 19 57 ice steam, is supplied in theoutermost passageway 16. Allthree fluids are, of course, supplied underpressure for ultimate mixing in the flame area of the burner. Whilewater is fed to the passageway 17, it will be partly or even mostlyvaporized in passageway 20 and issue into the reaction zone as steam.Advantageously vaporization is not complete until the point of dischargefrom the passageways 20, so as to obtain the maximum cooling of thesepassageways. Thus, a blanket of steam is maintained between thereactants at their point of issue into the reaction zone. Note also thatthe two passageways 21 which convey the liquid hydrocarbon to the flamearea are inclined in parallel vertical planes, in order to impartsubstantially swirling motion to the liquid hydrocarbon as it enters theflame area.

While it is not definitely known, it is believed that the hottest areain burners of this type is that area immediately surrounding the oxygenpassageways 19 at the point where they exit to the flame area. It isfurther believed that the introduction of Water (steam) at a pointintermediate the oxygen and fuel openings serves several purposes.First, it provides introduction of a cooling medium at a critical point.Secondly, since the water is vaporized to steam in the burner head andenters the flame area with some force, it promotes more thoroughmixingof the oxygen and hydrocarbon components of the suppliedreactants. Thirdly, it is believed that the pressure of the issuingsteam prevents droplets of unvaporized liquid hydrocarbon issuing fromthe passageways 21 from impinging upon the flame exposed surface of theburner and the openings therein. In that way the steam serves as afurther aid in preventing cloggingof the several burner orifices. Whileit is true that the presence of the steam in this area of the flowgenerator may impair, to a limited extent, the efliciency of theoperation, the other beneficial eifects listed above are so important,as regards permitting continuous operation with a minimum of shut downs,that the use of water or steam in this manner appears to be entirelyjustified.

While mention has been made of adding steam to the oxygen stream,nevertheless it is contemplated that the steam may be omitted and eitherrelatively pure oxygen or enriched air, for example, air containing atleast about 40% oxygen, charged to passageway 16.

Provision may be made for injecting some steam into the oil streamentering the conduit or passageway 18, particularlyin the case ofrelatively heavy viscous oils. Each of the reactant streams may beseparately preheated to temperatures of 600 F. and higher prior topassage to the burner. Preheating the reactant streams to these hightemperatures aggravates coke formation in the oil passage and on theface of the burner, particularly when charging heavy low-grade oil. Thepurpose of the burner of this invention is to prevent this coking.

The burner of this invention is particularly useful in flow-type gasgenerators. U. S. Patent No. 2,582,938, issued January 15, 1952, to LeonP. Gaucher and Du Bois Eastman, for Manufacture of Synthesis Gasdiscloses one example of a gas generator with which this invention canbe used. This type of generator is free from catalyst or packingmaterial and is characterized by having an internal surface area of notmore than about 1.5 times the area of a sphere of equal volume. It isoperated under pressures ranging from atmospheric to 600 pounds persquare inch gauge or higher and at temperatures ranging from about 2000to 3000 F., the re- 3 action temperature being maintained autogenouslyexcept for the aforementioned preheating of the reactants.

One or more burners may be provided for the generator, depending uponthe generator size. In a typical burner for a generator of about 2 cubicfeet internal volume, and capable of producing about 25,000 cubic feetof synthesis gas per hour, the annular passageway 16 is about .10 inchwide, the annular passageway 17 is about .06 inch wide, while thepassageway 18 is about .12 inch in diameter. The two oil orifices orpassageways 21 are about .05 inch in diameter. The passageways 19 areabout .12 inch in diameter, while the passageways 20 are about .06 inchin diameter.

The longitudinal axes of the passageways 19 and 21 form angles of about20 to 30 with the longitudinal axis of the passageway 18, while the axesof the passageways 20 form angles of about 45 therewith.

From the foregoing it will be apparent to those skilled in the art thata greatly improved burner head has been shown and described herein. Itwill be equally apparent that the specific structure shown in theaccompanying drawings is merely illustrative of a preferred embodiment,and that many structural variations are possible within the scope of theappended claims.

I claim:

1. A burner assembly for use in a flow type gas generator for conveyingto the generator reaction zone a stream of hydrocarbon and a stream ofoxygen containing gas comprising: an elongated burner terminating in aflame exposed burner head having a substantially flat surface portiondisposed perpendicular to the longitudinal axis of said burner and asingle frusto-conical shaped depression located centrally of said flatsurface portion and converging inwardly continuously from said flatsurface to a horizontal plane surface spaced inwardly from said flatsurface; a first reactant conduit leading to said head and terminatingin at least one reactant discharge opening in said plane surface of thebase of said frusto conical shaped depression of said burner head; meansfor supplying fluid fuel to said first reactant conduit; a secondreactant conduit coaxial with and disposed about said first reactantconduit and terminating in at least one reactant discharge opening inthe conical side wall of said frusto-conical depression of said burnerhead; means for supplying an oxygen containing gas to said secondreactant conduit; a coolant conduit coaxial with and disposed betweensaid first and second reactant conduits and terminating at the conicalside wall of said frustoconical depression in a plurality of openingsarranged in a circular pattern and being disposed intermediate saidreactant discharge openings; means for supplying water to said coolantconduit, whereby water conducted through said burner in said coolantconduit will be vaporized into steam which issues from said plurality ofopenings, thereby efiectively cooling said burner; and an annularcoolant chamber in said burner head located under said flat surfaceportion and disposed around all of said discharge openings.

2. A burner assembly for use in a flow type gas generator for conveyingto the generator reaction zone a stream of hydrocarbon and a stream ofoxygen containing gas comprising: an elongated burner terminating in aflame exposed burner head having a fiat surface disposed in a planeperpendicular to the longitudinal axis of said burner and a singleshallow frusto-conical shaped depression in the center thereof; meansdefining an axial hydrocarbon passageway in said burner terminating in aplurality of openings at the surface of said depression and beingdisposed angularly with respect to each other and with respect to theaxis of said passageway to impart a swirling movement to the hydrocarbonissuing therefrom; means for feeding a fluid hydrocarbon to saidpassageway; means in said burner defining an annular oxidizer passagewaydisposed about and concentric with said hydrocarbon passageway andterminating in a plurality of orifices arranged in a circular pattern atthe conical side wall of said frusto-conical depression; means forfeeding an oxygen containing gas to said last recited passageway; meansin said burner defining an annular coolant passageway concentric withand intermediate said hydrocarbon and oxidizer passageways, andterminating at the conical side wall of said flame exposed burner headin a plurality of openings arranged in a circular pattern intermediatesaid hydrocarbon openings and said oxidizer orifices; means forsupplying water to said coolant passageway, whereby water conductedthrough said burner in said coolant passageway will be vaporized intosteam which issues from said plurality of openings to effectively coolsaid burner; means defining an annular coolant passageway in said burnerhead underneath the flat surface of said flame exposed burner head, saidannular passageway being disposed about all of said other passagewaysand discharge openings and orifices; and means for feeding a coolantthrough said last recited coolant passageway.

References Cited in the file of this patent UNITED STATES PATENTS733,693 Bladon July 14, 1903 872,288 Koons Nov. 26, 1907 903,736 LeeNov. 10, 1908 1,228,818 Pictet June 5, 1917 1,796,299 Nolan Mar. 17,1931 1,830,574 Thwing Nov. 3, 1931 1,841,698 Barber Jan. 19, 19322,231,244 Berthiaume et a1 Feb. 11, 1941 2,310,704 Mulholland Feb. 9,1943 2,368,373- Morrell Jan. 30, 1945 2,453,378 Lubbock Nov. 9, 19482,609,658 Goddard Sept. 9, 1952

